A new paper has come out from the Sala Lab in Oecologia. The paper entitled “Preference for different inorganic nitrogen forms among plant functional types and species of the Patagonian steppe” shows that shrubs and grasses absorb preferentially different forms of inorganic nitrogen. Grasses which have fibrous and shallow roots absorb inorganic N mainly as ammonium, which is the main inorganic N form in the upper soil and has limited mobility through the soil profile. In contrast, shrubs that explore deep and N-poor soil layers and have non-fibrous roots, have kinetic adaptations to preferentially take up nitrate. Such differences allow for the complementary use of N between grasses and shrubs and suggest a more thorough exploitation of resources by diverse ecosystems than those dominated by just one functional type.
